This invention relates generally to automotive vehicle doors that are equipped with a moveable window pane of glass and more particularly to a window regulator for raising and lowering the window pane.
It is well known in automotive vehicles to mount a window pane of glass in the vehicle door for movement between open and closed positions. The position of the window pane is controlled by a window regulator which commonly includes a lift arm having a lower end pivotally mounted on the door panel. An upper end of the lift arm carries a roller that is mounted in a sash panel that is attached to the bottom of the window pane. As the lift arm is rotated, the window glass is raised and lowered. Lift arm window regulators typically include a relatively large sector gear that is carried by the lift arm. A crank shaft operated by either a manual crank handle or an electric motor drives a pinion gear that meshes with the sector gear. Rotation of the crank shaft rotates the pinion gear which in turn rotates the sector gear to rotate the lift arm and raise or lower the window pane.
In some circumstances, it is difficult to package a lift arm window regulator because the sector gear carried by the lift arm is relatively large and the crank shaft must be located where the pinion gear meshes with the sector gear.
It is known to use a rack bar in a window regulator mechanism. For instance, U.S. Pat. No. 1,937,662 granted to Stanley W. Nicholson Dec. 5, 1933 discloses a window regulator for a pullman car in which rack bars 38 and 40 are attached to window sashes 17xe2x80x2 and 17 respectively. Rack bars 38 and 40 are located between window sashes 17xe2x80x2 and 17 with a window regulator R disposed between the rack bars 38 and 40. Window regulator R has a handle 33 that selectively rotates gears 27 and 29 that engage rack bars 38 and 40 respectively to raise and lower window panes 13 and 14. Handle 33 shifts axially to select which gear is rotated.
In one position handle 33 rotates gear 35 which meshes with and rotates gear 30. Gear 30 drives gear 29 via a spring clutch 57 to raise or lower window pane 14. When handle 33 is shifted to another position, gear 35 which is attached to handle 33 meshes with and rotates gear 32. Gear 32 then drives gear 27 via a second spring clutch 57 to raise or lower window pane 13.
The Nicholson window regulator is complicated mechanically, requires considerable space and is not suitable for an automotive application.
U.S. Pat. No. 2,115,632 granted to J. H. Hanley Apr. 26, 1938 discloses a device for raising and lowering automobile window glass 3 comprising a rack bar 5 that is attached to window frame 4. Rack bar 5 is raised and lowered by a five bar linkage comprising links 17, 18, 14,15 and 10. Upper input link 17 is rotated by a handle 16 and lower output link 10 terminates in a sector gear 9 that drives a compound gear 11/13 that meshes with the rack bar 5. Handle 16 is rotated about 90xc2x0 to lower window 3.
The Hanley window regulator is complicated mechanically and still requires considerable space.
U.S. Pat. No. 2,336,530 granted to Daniel L. Chandler et al Dec. 14, 1943 discloses a floating drive mechanism for raising and lowering an automobile window comprising longitudinally spaced vertical rack bars 36 and 37 attached to the door and a cooperating drive mechanism that is attached to the window sash 15. The drive mechanism comprises an electric motor 24 that drives worm gears 26 and 27 that is turn drive pinion gears 32 and 33 that mesh with rack bars 36 and 37 respectively. The Chandler window regulator is also complicated mechanically and requires considerable space.
It is also known to use a rack that is pivotally attached to the lift arm rather then a fixed sector gear to rotate the lift arm. See for instance U.S. Pat. No. 1,640,864 granted to Carl Ungerman Aug. 30, 1927 and U.S. Pat. No. 6,035,579 granted to Brian H. Staser et al on Mar. 14, 2000. These known rack and pinion window regulators offer some packaging advantages particularly in terms of locating the crank shaft. However, these known rack and pinion window regulators still take up a considerable amount of space in the hollow shell of the vehicle door.
This need for considerable space is becoming a problem as more and more components, such as speakers, power door locks, handle operating linkages, wiring harnesses, etc. are packaged in the door shell. Accordingly, there is a need for a compact window regulator that takes up very little space in the door shell.
The invention provides a rack and pinion window regulator for a door for an automotive vehicle that takes up very little space in the door shell. The door has an inner metal stamping and an outer metal stamping that are secured together along a perimeter to form a shell that includes an upper window frame and a lower hollow body. The window regulator is preferably part of a module that includes a structural belt beam of the door. The window regulator also includes a drive assembly, a rack, a window pane and a window guide channel which are also preferably part of the module. The window guide channel has a rear run and optional header and front runs, the window guide channel being attached to structural belt beam so that the front run is attached to a forward end of the belt beam and the rear run is attached to a rearward end of the belt beam. The window pane has a front edge that travels in the front run and a rear edge that travels in the rear run. The rack is disposed in the rear run and attached to the rear edge of the window pane. The drive assembly which is preferably mounted in a rearward end portion of the structural belt beam by a bracket supports a reversible electric motor. A pinion gear that is secured to an output shaft of the reversible electric motor meshes with the rack so that the window pane is raised and lowered by the reversible electric motor. The rack is preferably made of a Teflon impregnated composite material and the pinion gear is preferably made of a Teflon coated powdered metal to reduce noise and friction. Teflon is the tradename of E. I. du Pont de Nemours Co., Inc. for polytetrafluoroethylene.